RUSTSEC-2026-0256

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Source

https://rustsec.org/advisories/RUSTSEC-2026-0256

Import Source

https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0256.json

JSON Data

https://api.test.osv.dev/v1/vulns/RUSTSEC-2026-0256

Published

2026-08-11T12:00:00Z

Modified

2026-08-12T10:30:18.189895730Z

Summary

Panic-safety unsoundness in `truncate_back`, `truncate_front`, `clear`, and `extend_from_slice` (use-after-free / double-free)

Details

Several methods in circular-buffer drop elements before updating the buffer's start/end metadata. If an element's Drop panics during the drop, the metadata update is skipped, so the buffer still treats the already-dropped elements as live. When the buffer is later dropped (or used after the panic is caught), those elements are visited again — a use-after-free / double-free reachable from safe Rust.

Impact

CWE-415 (Double Free): the same allocation is freed twice.
CWE-416 (Use-After-Free): a freed allocation is accessed during a repeated Drop.

Reachable entirely from safe Rust via catch_unwind with element types whose Drop can panic.

Fix

Fixed in circular-buffer 2.0.1 by adjusting the buffer's start/end metadata before the elements are dropped.

Database specific

{
    "license": "CC0-1.0"
}

References

Affected packages

crates.io / circular-buffer

Package

Name: circular-buffer; View open source insights on deps.dev
Purl: pkg:cargo/circular-buffer

Affected ranges

Type: SEMVER
Events: Introduced

0.0.0-0

Fixed

2.0.1

Ecosystem specific

{
    "affected_functions": null,
    "affects": {
        "os": [],
        "functions": [
            "circular_buffer::CircularBuffer::clear",
            "circular_buffer::CircularBuffer::extend_from_slice",
            "circular_buffer::CircularBuffer::truncate_back",
            "circular_buffer::CircularBuffer::truncate_front"
        ],
        "arch": []
    }
}